Journal archives for June 2020

June 01, 2020

Green alder sawfly (Monsoma pulveratum) overwintering under bark of beetle-killed spruce

Beetle killed trees can become homes for other forest pests, like these green alder sawfly pupae on a white spruce. Adults will soon emerge & lay eggs on nearby alder, where larvae will hatch & start munching.

Posted on June 01, 2020 15:30 by awenninger awenninger | 0 comments | Leave a comment

June 19, 2020

Western tent caterpillar (Malacosoma californicum)

Have you noticed any of these caterpillars and ‘tents’ in alder or cottonwoods? They have been reported in Ketchikan and the Forest Service State & Private Forestry would like your help to determine where they occur. If you notice western tent caterpillars, take a picture and upload it to iNaturalist to help us collect data on these forest pests.

Posted on June 19, 2020 15:53 by awenninger awenninger | 0 comments | Leave a comment

June 24, 2020

Sunira verberata - Hardwood defoliation near Cooper Landing, AK

Areas of heavy hardwood defoliation were found along Juneau Creek Road near Cooper Landing. Dark-colored caterpillars were found on aspen, birch, willow, cottonwood and wild rose. Some understory aspen had very little leaf surface remaining besides leaf midribs.

These caterpillars appear to be pupating at this time and will emerge as adults in the fall. You can help the Forest Health Protection team track these types of outbreaks by uploading your observations and pictures to iNaturalist.

For more information on Alaska Forest health visit:

Posted on June 24, 2020 23:10 by awenninger awenninger | 0 comments | Leave a comment